. "Reviewed: D'Eustachio, P, 2009-12-11"^^ . "Edited: Jupe, S, 2010-03-01"^^ . "Urotensin-II (U2) is a vasoactive 'somatostatin-like' cyclic peptide originally isolated from fish spinal cords. It was found to activate GPR14 later renamed Urotensin II receptor (U2R).
U2 is the most potent known vasoconstrictor. A second ligand for U2R, urotensin-related peptide or Urotensin 2B, was identified as an extract from rat brains, and shown to activate rat and human U2R."^^ . "Authored: Jupe, S, 2009-10-27"^^ . . . . . . . "Urotensin-2 receptor binds urotensin-2 and 2B"^^ . . . .